In recent years, portable electronic apparatuses, such as portable telephone terminals and game machines, have been popularized, and the number of rechargeable batteries built in these apparatuses has been increased more and more. In addition, concurrently with the development of wireless radio technology, the application of RFID (Radio Frequency IDentification) technology for sending signals with minute electric power has been expanded. Specifically, an active RFID with electric power is capable of communication to a distance of several hundred meters or more. Therefore, there are increasing expectations for its use in healthcare for cattle, horses, and so on in a pasture, safety management for children on their way to and from school, and so on.
On the other hand, to maintain and improve the global environment, researches and developments of a battery with less environmental impact as possible also have been actively conducted. Among them, it is widely considered that the energy generally consumed uselessly and unconsciously may be converted into electric energy to recharge batteries and that this energy may be used as electric power supplies of portable apparatuses or the like.
Patent Document 1 discloses an oscillation type power generator that employs a system in which a plurality of permanent magnets magnetized in the longitudinal direction thereof is arranged in such a manner that the poles with the same polarity are opposed to each other at a minute distance and unified together to provide a movable magnet; and the movable magnet is allowed to move through a plurality of coils serially connected in such a manner that adjacent coils have opposite polarities.
Patent Document 2 discloses a power generator in which a plurality of magnets is joined such that the surfaces of the poles with the same polarity are opposed to each other and coils are connected in series in such a manner that adjacent coils have opposite polarities.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-296144
Patent Document 2: Japanese Unexamined Patent Application Publication (Japanese Translation of PCT International Application) No. 2006-523081